Cushion spring and method of making the same



C. A. TEA

April 13, 1948.,

CUSHION SPRIN AND METHOD oF MAKING THE' SAME Filed June 22, 1944;l

2 Sheets-Sheet 1 l INVENTOR. @LA R K A. TE A MM2/HMM ATTORNEYS C. A. TEA

April 13, 1948.

CUSHION SPRING AND METHOD OF MAKING THE SAME 2 Sheets-Sheet 2 Filed June 22, 1944 INVENTOR.

CLARK A. TEA

ATTORNEYS Patented Apr. 13, ,1948

UNITED STATES .-NPATENT OFFICE CUSHION SPRING AND METHOD F MAKING THE SAIWE Clark A. IIea, Detroit, Mich. Application June 22, 1944, Serial No. 541,489

The invention relates to cushion springs and forms a continuation in part of my former application, Serial Number 521,413, led February 7, 1944, now abandoned.

It is the object of the instant invention to simplify the construction and reduce the cost of manufacture while maintaining all of the advantages of the construction forming the subject matter of the parent application. To this end the invention consists in the constnuction and method of forming the same as hereinafter set forth.

In the drawings:

Fig. 1 is a plan view of my improvedcushion spring;

Fig. 2 is a cross section on line 2 2, Fig. 1;

Fig. 3 is a side elevation;

Fig. 4 is a plan view of the blank from which the spring members are formed;

Fig. 5'is a perspective view of a portion of one of the spring members; and

Fig. `6 is a view similar to Fig, 4 showing a slightly modified construction of the blank.

As set forth in my earlier application above referred to, the cushion spring comprises a plu- 5 Claims. (Cl. 155-179) rality of elements each formed of a sheet metal i strip bent into zigzag form and having its opposite ends welded or otherwise attached to an adjacent element. To distribute and equalize the stresses in different portions of these members when under load, portions of the metal are cut out so as vto leave a greater cross section at the bends than intermediate the same. The metal thus removed is scrap which cannot be used in any other part of the structure. My improved construction also has a plurality of elements formed from sheet metal bent into a zigzag form, and these elements are formed with a differential cross section to produce substantially the same 'distribution and equalization of stresses as in the former construction. However, instead of obtaining this result by cut-outsnforming scrap metal, I blank the original sheet so as to utilize substantially the entire area thereof for forming the zigzag members.

As shown in Fig. 4, a rectangular sheet A of metal of proper gauge is cut by blanking punch and die members to form two identical blanks B and B with interspersed intertting portions. Each of these blanks has at one side thereof a strip C or C having parallel edges and between this side and the opposite side a series of spaced portions D, D', etc. having sinusoidal edges. The shape is such that the portions of thesheet E, E', etc. between adjacent portions D, D' are the same in shape as theseportions but in staggered relation thereto. The blank B has at one end thereof an uncut portion F of somewhat greater width than the dimension between adjacent crests of the members D, D. A similar portion F' at the opposite end of the sheet will be inte. gral with the portions E, E. One sideoedge of the blank B is parallel tothe edge of the rectangular sheet, this resulting in a strip C with parallel edges similar to the strip C but integral with` the end portion F'. `As a consequence, the last portion D2 has one of -its edges sinusoidal and the other straight, and this isalso true of the portion E2 which is integral with the end portion F of the blank B'. Thus, the only portionsA of the original sheet which are not utilized in form-v` ing the blanks B, B' are the small rectangles G and G.

The blanks B and B' may be bent into zigzag elements H by any suitable form of apparatus which need not be described in detail. It will be sulicient to say that return bends are` formed along the lines I, 2, 3, 4 and 5 resulting in a structure such as shown in Fig. 5. A plurality of these zigzag elements are then secured to each other by arranging them in parallel rows so as to overlap the bottom portions F, F', welding or otherwise securing them to each other. In the same manner the sub-portions D3 of the portions D, D', etc. overlap the adjacent zigzag elements and may be secured thereto by welding. However, to obtain symmetry the zigzag elements at opposite ends of the assembly are reversed in relation to each other.

If it is desired to make a spring seat structure with its forward edge higher than the rear edge, as shown in Fig. 2, it is only necessary to progressively increase the dimensions between successive crests of the sinusoidal members. This is shown in Figs. 1 and 2. The gauge of sheet metal selected for forming the blanks may also be varied in accordance with the load to be carried.

While I have used the term sinusoidal in describing the contour of the strips, this term is used generically. It is, however, desirable to avoid sharp angles as these would localize stresses which might result in fracture.

The modified construction of blank illustrated in Fig. 6 is th'e same as that in Fig. 4 with the exception that the portions C, C', D2 and E2 have been omitted. All of the portions D, D", E, E' are, therefore, symmetrical having sinusoidal contours on opposite edges thereof. 'Ihere is, however, a scrap portion G2 at each edge of the original sheet in addition to the portions G and 3 G'. This slightly increases the Waste area but not to a detrimental extent.

To complete the spring, an annular border Vframe may be attached to the upper end thereof.

Thus as shown in Figsl, 2 and 3, a wire frame I is secured to the upper ends of the members H by means Vof strips J bent around said frame and overlapping and attached to the upper end portions of the adj acen-t.v members. l I

The strips. C and C.r form portions off thebase of the spring frame which are at right angles to the portions F and F',

What I claim as my invention is; A

1. A spring comprising a strip of uniform thick-',-V ness having a sinusoidal side edge contour, said strip being bent transversely to its length aitsuc.-V cessive crests of the curve into a zigzag form.

2. A spring comprising a strip having its side edges of opposite sinusoidal contours, said strip being bent transversely to its length at successive crests of the sinusoidalcurves into a zigzagA form. 3L Ai spring comprising spaced strip portions connected tol` each therv at.. one end by a' transver's'el'y? extending portiom each of said strip' por]- t'iis Having its Side edges' of opposite sinusoidal' cdntours and' being. bent; transversely toy its' length at successive crests of. the sinusoidal curves i'rtol azigzag form.

4.. A. spring comprising a plurality of members each member being formed of an.integra1 blank. Having a. plurality oi spacedv strip portions` con:v nested at', one. end .by a transversely extending. reatgul'ar portion. each of said' strips` having its side,` edges', of Opposite. sinusoidal; cdnteurs and beirlgberit transversely te its lengthv at succes..

sive. erestsoi the. sinusoidalcurves. into. zigzag ior'm, said members. being arranged with the spaced portions thereof in parallel rows `having -Y said rectangular portions in adjacent rows overlapping. and secured toeach other andthe opposite end portions of the Strips neacl'i row overlapping and secured tothe adjacent end portions. in an adjacent. row.

NITED-l PATENTS Number Y Name., Date 94,025. Perry ..Aug. 24, 186.9 219,617V Cody Mr Sept. 16, 1879 3l) 1,095,661 Moulton May 5', 1914 1,433,138 KIuSe. I.. 0617...'24, 1922v 1,893,093 Murray et al. Jan. 3, 193.3 2,002,399 Kaden n May 21,1935 2,201,991. Freund .f May 28, 19.40 2,239,062" Tall'm'adge Apr. 22, 194,1 2,309,469 Marcuse Jan.v 26, 1943 FOREGN Number Country Y Date 3,776 Great Britain Feb. 12, 1897 14,518 Germany Aug` 9,y 18.8.1.. 75,577 Germany June 8, 1894 116,358 France Jan.. 6, 18.77

5. A spring comprising a plurality of members securedto the adjacent end portions in an ad-V jacent-row, the dimension between the bent crests irrone member differing from'the corresponding dimension in successive members to vary the height thereorv andV resilient pressure thereof under loa-d.; Y Y

CLARK A. TEA.

REFERENCES errno' The following references are of record inV the file of this patent: 

